Hi Kev
Answer is yes you can have independent stamps and there was nothing said about software. I asked and they said there is no need for any change.
Long story though. I will start from beginning... I bought car and I thought was bit slow, comparing to my old Alfa 159 1.9 JTDM diesel Lexus is slow. I was surprised to drive such a mule and it has 2.2 engine. So on Saturday I decided to clean EGR, clogged. Few days later I had P2002. Then I went to Lexus to buy extended warranty. I know, bit cheeky. They looked into my service book and approved me to have warranty for 495£. But I had to do service with Lexus as they need to be sure car is ok. What they do though on service for 149£ is just oil change!
I came back to them few days later with error of curse. Then Lexus Leeds told me that there is something wrong with my service history because they called last service station from my book and apparently that place just stamped book because they were mates or family with previous owner. But Garage admitted car was serviced there but without invoice. So they declined my repair through warranty because I came 2 days after since I signed up for warranty, I had existing fault and I didn't have service with them yet.
Final now. I had to buy EGR myself now, Lexus guy cancelled my warranty without my permission. He said I can sign up again but I need to do service at Lexus first then sign up warranty again but I would not be able to claim that EGR again. I am very disappointed because many people here get that repair for free as it is a common fault and I brought printout from this forum that is happening but no I didn't get it for free. They said my car in March is 8 years old and all of you getting free repairs were under 7.
I wrote letter to Lexus, will see